Project description

Abstract

The project will train Tanzanian scientists and students in sampling, analyzing and interpreting data on physical, chemical and biological conditions in Lake Tanganyika, Tanzania. By combining novel research and capacity building of regional researchers, lake managers and key stakeholders of the lake, we aim to set the grounds for an improved and informed long-term sustainable environmental management of natural resources in Lake Tanganyika in an era of climate change and rapid human population growth.

 

Background

Lake Tanganyika with fishing boats. Photo Peter Staehr

Climate change will disproportionately affect developing countries. The project will provide fundamental information regarding the extent to which climate-driven changes are influencing the dwindling pelagic fish catches in Lake Tanganyika. While some studies have indicated a strong interaction between climate and fish yields, others have disputed this relationship. However, systematic collection of data on lake physics, primary production and fisheries and application of novel lake models that account for interactions between climate and fish yields will provide a powerful way to obtain valuable new insight that may resolve the current dispute. Our study incorporates all possible drivers of both ecosystem change and fisheries variability and is therefore of high relevance for Tanzania as well as the other riparian countries in the Lake Tanganyika basin. This is particularly important as informed, proper and sound management of the fishery resources in the lake hinges on a solid data foundation.

Specific objectives

  • Build regional capacity in lake quality monitoring and sustainable management of fisheries
  • Improve our understanding of climate-driven changes in lake functioning and fisheries productivity of Lake Tanganyika
  • Gather essential data A) to develop lake ecosystem models and B) to inform local citizens, especially small-scale fishermen, of lake conditions to promote sustainable fisheries.
Lake Tanganyika basin
Lake Tanganyika basin

Lake Tanganyika and its basin

Lake Tanganyika is an African Great Lake. It is estimated to be the second largest freshwater lake in the world by volume, and the second deepest, in both cases, after only Lake Baikal in Siberia, it is also the world's longest freshwater lake. The lake is divided among four countries – Tanzania, the Democratic Republic of the Congo, Burundi, and Zambia, with Tanzania (46%) and the DRC (40%) possessing the majority of the lake. The water flows into the Congo River system and ultimately into the Atlantic Ocean.

Catchment area

231,000 km2

Max. length

673 km

Max. width

72 km

Surface area

32,900 km2

Average depth

570 m

Max. depth

1,470 m

Water volume

18,900 km3

Residence time

5500 years

Shore length

1,828 km

Surface elevation

773 m

Lake monitoring

A unique dataset on the physical, chemical and biological properties of Lake Tanganyika will be collected using standard ship-based sampling and buoy systems. High frequency data from the buoys will allow us to calculate thermal stability of the water column and determine the frequency and magnitude of upwelling events. We will assess changes in nutrient concentrations from water samples and nutrient limitation using plankton stoichiometry. We will calculate lake-wide algal biomass and primary production using metabolism calculated from buoy data and chlorophyll measured weekly by scaling to the full lake using remote sensing. We will compare our values and findings with those obtained in previous studies to determine the response to climate change.

Placement and configuration of planned buoys used for high frequency lake monitoring.
Placement and configuration of planned buoys used for high frequency lake monitoring.